Rila (Bulgarian: Ðèëà [ˈrilə]) is a mountain range in southwestern Bulgaria and the highest mountain range of Bulgaria and the Balkans, with its highest peak being Musala at 2,925 m. The massif is also the sixth highest mountain in Europe (when each mountain is represented by its highest peak only), coming after the Caucasus, the Alps, Sierra Nevada, the Pyrenees and Mount Etna, and the highest between the Alps and the Caucasus. The larger part of the mountain is occupied by the Rila National Park.

The name Rila is allegedly of Thracian origin and is thought to mean "well-watered mountain", owing to Rila's abundance of glacial lakes (about 200) and hot springs in fault areas at the base of the mountain. Some of the Balkans' longest and deepest rivers originate from Rila, including the Maritsa, the Iskar and the Mesta.

Culturally, Rila is famous for the Rila Monastery, Bulgaria's largest and most important monastery founded in the 10th century by Saint John of Rila.